I've been working on generative LEGO assembly models recently, but there are similar projects already, so I wanted to try some harder cases: specialized parts (incl. technic), multi-modal prompting (incl. using images, 3D meshes or almost any input), constrained inventory (so you could upload just parts you have), ensuring physical validity and generating buildable instructions, being able to tweak, modify or rebuild entirely an existing build etc.

TL;DR the pipeline got more complex than expected and I ended up with an agentic harness leveraging recursive program synthesis, combinatorial diffusion, semantic 3D search and operations on assembly hypergraphs.

Yet I am quite happy with the result. It should be able to handle as well a functional mechanism, LEGO robot, artistic landscape or fancy animal.

Most importantly, it also checks for subgraph matches of builds present in catalogue, being able to check (and possibly enforce) originality and prevent copying existing MOCs.

Have fun!